1. Field of the Invention
The Invention is related to the field of vehicular traffic control and particularly to portable traffic lights. The Invention is a battery-powered, center-of-intersection portable traffic light featuring a control system, radio communication among two or more of the portable traffic lights, telephone text messaging to an operator, traffic detection and preemption. Each portable traffic light of the Invention may act as either a master controlling a plurality of other portable traffic lights or as a slave being controlled by another portable traffic light of the Invention.
2. Description of the Related Art
Traffic control on roadways is essential for the efficient use of the roadways and for the prevention of traffic accidents. Traffic control in the form of a traffic light is particularly useful at intersections of two or more roadways. For purposes of this application, the term “traffic light” means an apparatus having at least one light source and capable of exhibiting at least a red and a green light to direct an operator of a motor vehicle to stop or to proceed. The use of traffic lights is well known. Colored lights to control the movement of traffic were first used in London in the nineteenth century. Red-green electrically powered traffic lights have been in use in the United States since 1912 at the latest. The first three-color traffic lights were introduced in New York and Detroit in 1920. The first manually-controlled interconnected traffic signal system was used in Salt Lake City, Utah in 1917. Automatic control of interconnected traffic lights was introduced in 1922 in Houston, Tex.
In past years, incandescent lamps were used to create white light and colored filters were used to filter out all but the desired shade of red, green or yellow. In recent years, the use of arrays of light-emitting diodes to generate light has become popular due to the substantial reduction in power consumption and the substantial increase in lamp life and hence reduction in service requirements.
In prior art stationary traffic lights, the term “preemption” refers to receiving by a traffic light of a signal from an emergency vehicle such as an ambulance or fire engine. The signal received from the emergency vehicle causes the traffic light to exhibit a green light to the emergency vehicle.
Prior art traffic lights do not teach the portable, self-contained traffic light of the Invention.